Marine gear



sept 5, 1950 c. J. McDowALL Erm. 2,521,239

ymums am Filed July 26, 1947 5 Sheets-Sheet 1 Sept 5, 1950 c. J. MGDowALL r- TAL 2,521,239

MARINE GEAR 5 Sheets-Sheet 2 Filed July 26, 1947 SePt- 5, 1950 c. J. McDowALL ETAL 2,521,239

MARINE GEAR Filed July 26, 1947 5 Sheets-Sheet 5 Zhwentors KBB SePf- 5, 1950 c. J. MGDowALL Erm. 2,521,239

MARINE GEAR Filed July 26, 1947 s sheets-sneer 4 f /e /W 7 ff f fo@ 7 f V21 f fz y U vf w /f/"\ 7% /z .J

` fl V lg (yf Qd 5u Y ff WQ,

venters Sept 5, 1950 c.,J. MCDQWALL Erm. 2,521,239

IARINE GEAR Filed July 26. 1947 5 Sheets-Sheet 5 .5r-li lwentors (www Patented Sept. 5, 1950 MARINE GEAR Charles J. McDowall, John E. Storer, Jr., and

Elmer A. Richards, Indianapolis, Ind.,

assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application July 26, 1947, Serial No. 163,790

(Cl. 'Z4-752) l 35 Claims.

The present invention relates to marine drive gearing for providing smooth drive ratio change between a marine engine and propeller drive mechanism, and more particularly therein to planetary change gear actuated by disc clutches and brakes energisled by fluid pressure means, controlled by pressure regulation means which guard against load stalling of the engine under heavy pulling and which assist in drive change by providing full and quick release of one drive means when another is to be connected.

Particular features of advantage appear in the utilization of a fluid pressure systemseparate from that of the engine, self-contained in the drive mechanism, which provides both for pressure lubrication and fluid servo ratio actuation. Special features in control of the fluid circuit elements for avoidance of drive overload, for assuring lubrication under high loads, and for regulation of the degree of fluid pressure actuation for drive ratio-determining brakes and clutches. Additional features involving special forms of clutch control valving and a non-reactive selector valve system also appear, the clutch control valving consisting of plural valves, one of which is subject to engine shaft speed for prevention of overload stalling and another of which, though located in a constantly-rotating member, is counterbalanced to eliminate centrifugal force eiect, and response to variations in line pressure or servo pressure variation for obtaining quick release of a loaded friction member. The ratio obtained, depends upon the numbers of teeth in these gears.

The invention as herein illustrated, utilizes two pressure control valves separate from the master ratio selector valve, in order to provide against clutch drag during shift of ratio, and to prevent engine stalling. The first of these controls only the pressure build-up on the direct drive clutsh while the second is effective during both forward and reverse drive.

These valves are radially placed and rotate with the flywheel, one of which varies pressure in response to engine speed, and the other being arranged to respond to variations in pump line pressurehaving its centrifugal component canceled by design of fluid pressure porting and radial spacing.

The gear group is lubricated in part thru pump line connections derived from the drive control and ratio actuation system arranged to assure pressure feed lubrication to the gears at all times Shaft.

The ratio actuators are of friction disc type. axially loaded by large annular pistons, and the servo cylinders are exhausted to the casing direct, when drained for drive disengagement.

The drive modification showni herein having a reduction gear unit in series behind the reverse gear which is lubricated from the pump line and control valve feed main by a direct branch tube which is removable from a convenient external point for cleaning without disturbing any of the adjacent members. i

The double-planet gear group is especially made for self-adjustment of both sun gear and annulus gear for equalization of load and-'quiet operation.

Other features, useful results and advantages appear in the discussion and demonstration'of the specification text following, descriptive of the constructions of the appended drawings in which:

Fig. 1 is a vertical sectional elevation of one form of the constructionof the invention utilizing a fixed reduction gear group in series with the main drive change'gear, and' built into the same housing.`

Fig. 1a is a detail section view of the barrel valve at the top of Fig.- 1.

Fig. 2 is a schematic diagram of the fluid pressure system and units involved in the Fig.- 1 structure, the units being generally sectioned as in Fig. 1 for clarity. The primary uid control channels are shown side by side in Fig. 2 whereas in the actual construction they lie in line with each other at right angles to the plane of the drawing of Fig. 1. The controls of Fig. 2 are shown as for drive in forward, direct.

Fig. 3 is a view like that of Fig. 2 with the controls shown as for reverse drive, as distinct from Fig. 2 and from Fig. l in which they are shown as for neutral, or no drive.

Fig. 4 is a sectional view taken at 4 4 of Fig. 1 to show the gear disposition of the ratio change drive unit and the lubrication flow pattern in this gearing.

Fig. 5 is a view like that of Fig. l but showing the transmission output shaft as the flnal driver of the propeller shaft as distinct from the twounit showing of Figs. l to 3 having the fixed reduction unit in the same housing. In practise, the main construction of Fig. 5 is readily converted to that of Fig. 1 by simple detachment and substitution of only a few parts.

Fig. 5a is a sectional view taken at 5-5 of Fig. 5 to show the port connections of the master valve control.

Fig. 6 is an enlarged view of the pressure dump I4 of Fig. 1, for controlling the pressure on the direct drive clutch. Fig. 7 is a view of the anti-stall valve I of Fig. 1. 6a is a sectional view of a brake presregulator valve similar to the clutch reguvalve of Flg. 6.

8 is a. diagrammatic development -view of surface porting of the manual control barvalveVofFigalto3and 5.

In Fig. 1, the engine iiywheel member` I is into a drum the flange portion Ia being to splines 2 to sun gear 2. The carrier 4 amxed planet spindles and 6 for two meshplanets sets 'I and 8, the planets 'I meshing ga-sgg araggagg gear i0, as shown in Fig. 4. This form of double planet arrangement has the property of providing reverse rotation if the annulus gear be held, with the load connected to the carrier. It is readily understood by reference to the sectional gure of Fig. 4. The splining of sun gear 3 to drum Ia, and the free mounting of annulus gear Il with its brake disc permits self-adjustment for load equalization of the gear The transmission output shaft II is piloted in the input flywheel hub Ib at I2 and is splined at I2 for the hub I4 of clutch plate I5 and at i6 for the sleeve il of carrier 4. Annulus gear I0 is connected to disc brake plate 20.

Power applied to sun gear 3 with load existing on carrier 4 causes the planets 'I and 8 to spin on their spindles 5, i, and drive annulus gear Il forwardly at an idling speed represented by a fraction in which the numerator is the diameter of the sun gear and the denominator the pitch line diameter of the annulus gear I0.

Now if clutch plate I5 be gripped to run with flywheel I, a locking couple is established between the carrier 4 and the sun gear 3, so that the amembly of Fig. 4 runs solid, at l-to-l ratio, or direct drive between shafts A and II.

With neither of clutch plate I5 or brake disc 2l engaged, the annulus I0 will idle forwardly at slow speed. as noted above.

When brake disc 20 is prevented from rotation annulus gear I 0 is stopped, and the reaction upon planets 1, 0 causes carrier 4 to rotate slowly backward. driving shaft iI reversely.

The rotation of shaft II is applied to gear 2i in mesh with gear 22 of offset load shaft 25, driving the latter at the reduction ratio of the gear pair 2i, 22, the shaft 25 rotating reversely to whatever rotation is applied to shaft I I.

Alternate actuation or engagement of clutch I5 or brake disc 20 therefore will drive shaft Il at 14o-1 ratio in the same direction as the engine llmft hub Ib, with load shaft 25 actually rotating reversely for "forward drive-and will drive shaft II at 1-1 in the opposite direction to engine shaft rotation, but shaft 25 will rotate in the same direction as the engine for reverse Transmission output shaft II is splined at 26 to engage the inner portion of gearbody 2i toothed at 28 and supported in bearings 2l and I2. The load shaft 2i is similarly splined at 32 for gearbody 22 toothed at 25 to mesh with gear teeth 28, and is supported on bearings 28 and 2T in casing 00. The external stub of shaft 2i k splined at 28 for the universal drive coupling sleeve 40.

The rear cover plate I00c of casing |00 is bored to permit the sleeve of coupling 40 to pass thru, and extends upward sulciently for removal of 2i andalso shaft ll,ifnecessary. Re-

sun gear 2 and the planets 8 meshing with moval of shaft 2l endwise permits gear 22 to drop downward whence dropping of the easing sump pan Illd permits its removal.

The gear arrangement provides a wide range of adaptability to different power installations and to different load conditions arising from varying boat loads and varying sizes and pitches of marine propellers.

By the present quick detachable shaft arrangement, a wholly different ratio pair of gears may be substituted in a given installation for special drive purposes. whereas in known commercial installations no such facility is provided.

The modification drive shown in Fig. 5 has parts numbers identical with those of Figs. 1, 2 and 3, but shaft II' has its splines 26 engaging the inner portion of output drive coupling 40', supported by double-row bearing 42 in casing |00', locked in place by collar-fitting IUI. In this version of the drive, shaft II is the load shaft of the unit.

The flywheel I is formed into a large annular cylinder 49 to accommodate clutch servo piston 50, the annular piston gripping the plate I 5 against the adjacent surface of ilywheel web Ia when the cylinder 49 is supplied with fluid pressure.

The casing |00 is formed to provide annular brake cylinder Il for piston 60, and removable clutch backing plate 6I locked in place by a lock ring, grips brake disc 20 with piston 60 when fluid pressure is supplied to cylinder 59.

Return springs 5I serve to release the grip of piston 50 when clutch pressure is removed, and return springs 63 perform the same operation for piston 60.

The sun gear 2 is mounted for floating movement under load, and being in contact with the meshing pinions I of the reduction group while being permitted to shift axially in its splines 2, tends to compensate for misalignment. Likewise the annulus gear I0 may move axially and self-adjust in the same manner. This peculiarity of the gear group provides two useful features, equalized distribution of load and selfcorrection for misalignment-resulting in quieter' and longer-lived gears. The vibration dampener unit D is of common form, and fulls the requirement of absorbing torque impulses over a range of torque calculated for the particular needs of the installation.

The whole unit is thoroughly lubricated i'or guaranteeing complete flooding and cooling of the servo and lubrication oil. The pump P is driven independently of the engine oil pump and as described herein utilizes an independent transmission oil system. It is possible to combine oil and pumping systems so as to use one oil body for both engine and transmission, and to cool the transmission oil thru the engine cooling system, but the disclosure herein operates satisfactorily without such expedients, which unless urgently needed. only increase weight and cost of themarino drive.

The clutch hub I4 is driven thru dampener mechanism D connected to the plate I 5 which is gripped by piston and web Ia when pressure is delivered by valve 94.

Piston 50 is annular and lies in cylinder 49 for axial motion only. Return springs 5I serve to release the grip of elements 50, Ia when uid pressure is released.

In neutral drive position, barrel valve V is rotated so that only passage 68 delivers pump line pressure. While this is connected to space 82 Shift of valve V from neutral to forward position connects passage 84 to port 85 to admit pressure to passage 88 and thence to space 88 thru tube-11, and via passage 82 to valve 84 for loading clutch l5.

Fig. 2 is a schematic diagram or the nuid pressure system of the invention, with the contributing units being shown in part section for illustrating the necessary flow connection paths.

'I'he pump P, upper right is driven by the engine shaft A` thru appropirate gearing and delivers output pressure to passage85 and line 88 leading to the inlet groove 52 and port space 52' of barrel valve V, rotatable in a bore of housing 288. The pump P draws from suction passage 54 and from line 55 connected to the oil reservoir of sump pan |88d. Valve 56 dumps pump line overpressure from passage 85 to passage 54, proportionally to pressure area and spring load.

The barrel valve V fits the bore in body 28| circumferentially, is end sealed at 51 and 58, and rotated by control handle 88. It has end grooves 88 and 82 cross-connected by internal passage 68. Input feed groove 52 is ported laterally at 64 to intersect port 85 open to passage 88 in housing |88. Port 61 of housing 288 is open to passage |58 in housing |88. Fig. 8 provides a I development view of the surface of valve V..

Port 18 is laterally connected to end groove 88 by passage 1| as shown in Fig. la, and is open to the space 12 behind reverse-brake piston 8l in cylinder 58 formed in housing |88. Return spring 63 unloads piston 58. v

With the parts as shown ln Fig. 2, valve V is feeding oil pressure to passages 88 and 88 while port 18 and connecting passage -1| are open to exhaust. Passage 68 is connected laterally to pipe 15 having spill port 16 above teeth 28 of output drive gear 2| for lubrication. This figure shows the direct drive control phase of operation.

Shaft II is bored to accommodate smaller diameter tube 11 connected thru radial passages 18, groove 88 and gland port 8|, to passage 88. The cylindrical bore space 82 external to tube 11 is connected by radial passages 83, groove 84 and gland port 85 to passage 88.

The adjacent end of the engine shaft A is hollowed out in a blind-end cylindrical space 88 open to tube 11, but blocked by plug 81 surrounding the tube. Radial passages 88 connect space 82 thru passage 89 to passage 88 leading to valve 8|, located in a radial bore in flywheel I.

Space 88 is connected laterally thru passage 82 in hub Ib to passage 88 leading to valve 84. As will be understood further in detail, valve 8| may relieve pressure in line 88 in accordance with variations in centrifugal force, and valve 84 feeds controlled pressure to direct drive clutch piston 58 in cylinder 49 formed in flywheel I.

Valve 84 is thimble shaped and is connected to the pressure oil feed only when barrel valve V delivers pressure to passage 68, tube 11 and space 88; that is; when forward drive is desired, and not so connected during neutral and reverse drive. 4Valve 84 has four external bosses of fullhore diameter, and is hollow as shown in Figs. 1 and 6. v'I'he space between the second narrow boss from the top and the third is drilled thru 6 at 84a so as to connect the interior of the valve with line 88. Spring |82 is recessed radially inward in a narrower portion of the valve bore, and presses the valve outward as shown in Fig. l, which tendency is resisted by the line pressure from passage 88 acting inside the valve onthe closed inner face area, so that if sumcient line pressure is available to actuate clutch I5, a variable regulation of pressure delivery may occur. if desired, until the valve 84 reaches its full inward position as shown in Fig. 2.

'I'he inlet port 84 is spaced radially from delivery port |85.and commonly joined to annulus 48 of clutch piston 58.

As valve 84 moves inward to expose feed port |84, from the Fig. l to Fig. 2 positions the fact that line 83 and passage |88 are exposed to equal land areas of valve 84 avoids any tendency for hydraulic latch-in effect. The mass of the valve 84 and that of spring |82 would tendpto oppose the line pressure action except for the fact that 'the radial mass of the fluid in the adjacent radial passages is so taken that the centrifugal force of the valve 84 and spring |82 is counterbalanced.

The rise of line pressure is preferred as a control factor for protecting the clutch I5 against low load slip abrasion. When sulcient pump line pressure is available to produce the desired clutch torque capacity,vvalve 84 permits clutch actuation when called for by the setting to forward position of handle 88' and valve V, but if for any reason, line pressure falls below that required to produce required clutch drive torque the spring |82 is so taken for calibrated force value that the port |84 is closed, (not shown in figures) opening cylinder 48 to axial relief pas- Y sage at port |88.

'I'he valve 84 of Figs. 1 and 6 serves to disengage the clutch I5 when the flywheel is rotating, under the control of the barrel valve V, and is therefore made sensitive only to drop in line pressure caused by removalcf pump line pressure as valve V is shifted to neutral and reverse. Within the speed ranges of operation, valve 84 is centrifugally balanced by the centrifugal force of the oil. mass ported to exert such force in opposition tc the centrifugal force of the valve and spring |82.

The anti-stall valve 8| shown in detail in Pig. 7 is spring pressed at 8Ia generally like the valve 84 placed opposite in the flywheel VI. Under the normal load of its spring 8Ia, it is held inward. The retainer plate 8Ib,seals enlarged' space IIb Aabove the valve 8| whichis hollow, and pump pressure delivered to passage 88 passes thru 88a to space 88h and iiows thru the hollow valve 8| to aperture 88e and to spill passage 88o open to sump I 88d. y

At a given low R. P. M. of ywheel I, the centrifugal force on valve 8| and incidentally that of the spring 8Ia becomes enective to raise the upper edge of valve 8| into the space 88h. where the feed of 88a tends to become restricted, to raise the pressure in the system to which passage 88 is connected. At high flywheel speeds valve 8| may seal against the inner face of plate 8|b. The effect of pump line pressure in passage 88 and space 88h is balanced out so that spring 8|a tends to open the valve 8| to full drain independent of the pressure and opposing the centrifugal force effect. The external cylindrical wall of valve 8| is plurally grooved to promote selfcleaning and alignment, and the inner end is single-taper formed concentric ywith the valve bore and exhaust passage 88e. In Figs. 2 and 3, valve u isshownmmgnspeeaposmo.

stalling, valve Under excsive overload. so as to avoid engine responding to flywheel speed develops inherent centrifugal force. `and is connectedinthecircuitsoastoreleasethe pressure of either of clutch piston 50 or brake piston 60, .tbelow a given is. P. M. or nywneei. 'rms arrangement protects the engine against stalling under load.

In Fig. 6. valve 04 is shown in blocking position, the port |03 feeding thru hol 94e in the groove between the central lands to the interior of the thimble-shaped valve 04, which being open at its lower end, tends to rise with the line pressure acting against spring |02. In the position shown the clutch cylinder ports |04, |06 are open to exhaust at port |06.

As the valve 0l rises, port |04 is opened to line pressure and exhaust port |06 is closed, trapping line pressure in the clutch cylinder 40, to load piston 50 and grip plate |5. During this interval the force of spring |02 may be so calibrated if desired, so that an extended pressure rise interval may be had, so that the clutch I5 is brought to engagement gradually.

In practise we nd that since the clutch cylinder passages are exposed by drainage prior to engagement, to atmosphere, the building up of loading pressure is obtained by a primary illling action inward which drives occluded air ahead of it before any considerable degree of pressure is felt on the clutch plates, at the same time the spinning of the oil body creates a rise of pressure in the peripheral zones, then in the inward radial' zones, which sequential action adds to smoothness of clutch engagement. We prefer, however to have the device 'pass thru this interval rapidly, since at small or zero R. P. M., of load shaft the clutch I5 cannot be damaged by quick torque application, and our preferred method facilitates ready maneuvering of a boat in close quarters. It should be remembered that valve 0| operates to relieve clutch pressure whenever the load torque pulls engine speed down below a predetermined flywheel speed.

The maneuvering facility of valve 94 is best appreciated in shifting out of forward, preparatory to coming alongside in a rough seaway, when it may be momentarily urgent to stop forward way by cutting in a few reverse revolutions of the propeller shaft.

A boat with forward way tends to drag the propeller into forward rotation and it is possible that if a long time interval is needed to break the clutch connection with the engine, the boat will ram the slip or dock before suflicient reverse R. P. M., can be applied to the propeller to bring the boat to rest on the water, or to reverse its motion.

Our control meets this test neatly and eHectively, since the instant barrel valve V connects clutch feed passage 66 to exhaust groove |28 of Fig. 8, the passage |06 drains the cylinder 49, and springs 5| unload the clutch I5.

The release of oil from the peripheral zones creates a subatmospheric condition which facilitates release of the pressure plate.

It should be observed that a predetermined pressure is required to obtain engagement by action of valve 94, consequently when valve 9| reduces the available pressure below thatlevel, disengagement thereupon occurs.

Valve V may be rocked to alternate neutral and forward positions for maintaining slow way on a boat operated in narrow S88. 100111 areas, the clutch I5 then delivering smallpulses of torque to the propeller shaft to steady the boat and avoid drift effect. l

The same type of operation may be carried on in reverse maneuvering. It is apparent that one may use a third regulating valve similar to valve 94 and operating in the connection of passages 10, 1|, 59 for controlling the feed to the reverse brake piston 60, if the no-stall characteristic needs to be accentuated in reverse shift. To achieve this application of the invention a correspondingvalve 94' located in the housing |00, ported like valve 04 may be used to control the feed to cylinder 50. We do not ilnd the third valve 94 to be needed in ordinary commercial boat practise.

Referring back to the pressure feed system of Figs. l to 3 and 5. passage 90, space 82 and passage 68 are connectedto the groove 52 of valve V at all times, therefore the degree of pump line pressure in 96 is always conditioned for either direct clutch or reverse brake loading by the centrifugal action of valve 9|. Consequently, whether in forward or reverse drive, valve 9| serves to relieve all of the line pressure the lnstant flywheel speed falls off below a given minimum, immediately unloading either clutch |5 or brake 20. It should be remembered that all common oil pumps exhibit variable pressure phenomena in their low-speed ranges. and in acceleration to normal operation condition go thru a rising pressure cycle. The present invention, in use with a defective or badly worn pump which is leaking and not furnishing proper oil pressure with speed, provides safeguards both against inadequate pump capacity for given ilywheel speeds, and against damaging slip due to excess load for a given speed.

LIhe development diagram of Fig. 8 is best compared with Figs. 2 an'd 3 for clear understanding of the control operation. The grooves 69 and 62 are shown at either end, cross-connected in dash line by passage 69'.

The face of the barrel valve V is recessed at |25 for cooperating with alocating guide screwpin shown, Fig. la and has a recess at |26, in-

dented or dimpled in the three angular positions for forward, neutral and reverse, to accommodate a common spring-loaded poppet |26 of Fig. 1a.

The main feed channel or groove 52 is sideported at 64 to feed forward drive pressure to clutch I5 and is side-ported at 14 to feed pressure to the reverse cylinder 59.

The end groove 69 is side-ported at 1| to intersect the port 10 of Fig. 3 when neutral is established. The internal passage 69 connecting the end ports 69 and 62 is radially ported at |21 into surface groove |28 which connects with passage 63 when the valve V is set in either neutral or reverse. Ports 1|, 10 also intersect in forward shift.

Although the operation of the present invention should be wholly clear from' the foregoing descriptions, we present below a .summary of the operation sequences for further clarity.

Upon starting the engine, with handle 60 of valve V in neutral position, flywheel rotates up to normal engine idling speed and pump P delivers rising pressure to line 96, which passes thru groove 52 to passage 68, oil pipe 15, spaces 82, 16 and passage 90. Valve 9| is preferably actuated at this point to block relief of pressure as shown in Figs. 2 and 6, so as not to dump the connecting system at exhaust passage e. Valve 94 remains in its outward position, held by spring |02, slncepassage 65 is open to exhaust at |28, and there is no pressure to shut ofi' exhaust |06 or to open port |03 to port |04 and cylinder 49.

As the operator revs up the engine, ywheel will have accelerated to a speed suiilcient to cause valve 9| to move outward against spring 9|a and close exhaust 90o. so that the overpressure trapped in the system may blow olf at pump relief valve 56.

Shift of lever 60 to forward connects groove 52 thru side port 64 to port 55 leading to passages 56, 11, 8S a'nd 93 to feed port |03 of valve 94. Ii valve 9| ls already closed due to R. P. M. of member l, the line pressure will shift valve 94 rapidly to admit pressure to port |04 and load the clutch piston 50 quickly at high pump pressure. If valve 9| is open when valve V is moved to forward position, the available line pressure will be less until increased R.. P. M. of member closes valve 9|, hence there will be a longer time interval before clutch I is fully loaded.

- load force. It is preferred to obtain these effects in the manner described than to rely upon a variable pressure eect from the servo pump alone. In practise we prefer to operate the pump P so as to provide a reasonably stable line pressure in passages 95, 95, 52 and 11 and to apply variable pressure actuation effects thru the porting and valving described.

Rocking of valve V from neutral to the reverse position of Fig. 3 connects groove 52 thru port 14 to brake cylinder 59. End port pressure in 69 is equalized by cross passage 69' to end port 62, avoiding axial jamming of valve V. This provides a proper exhaust outlet for leakage from groove to the space 52 between the adjacent `end of valve V and the seal.

In practise, passage 'l0 extends downward as in Fig. la, opening into oil-feed hole 10a to the right of carrier 4 to provide additional gear lubrication during reverse gear drive.

Space 82 external to tube 11 is connected thru passages |01, |08, and |09 for feeding lubricant to sun gear 3 drilled plurally and radially as shown in Fig. 4 to deliver lubricant under pressure to the gear teeth.

Shroud 99 for the lower portion of gear 22 assists in controlling the ow of oil to the top of the unit, and avoids sump churning.

Shift from forward to reverse may be made at any time without dwell in neutral.

Should such a shift be necessary, movement of barrel valve V to reverse transfers servo pressure from clutch passage 66 to reverse brake passage 10, and connects the various clutch line connected passages to exhaust. In practise, we nd it almost impossible to have a drive condition in which torque, even momentarily is supported simultaneously by clutch I5 and brake 20, because of the rapidity 0f draining of clutch cylinder at passage |05.

It does not appear necessary to reduce the throttle to below closure speed for valve 9|, to

make the direct-to-reverse shift, but if that is done, there is noticed a slight tendency for 10 lengthening of the time in hold.

If in starting up, one has to drive the boat in reverse, motion of handle 60' from neutral to reverse positions delivers pressure from' groove 52 of-valve V to side passage 14 and port 10 whence it passes to cylinder 59 of brake piston 00. Valve 9| may or may not control the brake loading fluid pressure, depending upon the R. P. M. of the engine, as described above in connection with the initial clutch loading interval.

Shift from reverse to neutral is obtained by continuing to deliver line pressure to valve 9| while connecting reverse cylinder 59 to exhaust at 10, 1|.

Side port 1| connected to end groove 59 in Fig. 8 is extended rotationally to a position oppo site side port 94 of groove 52 so that reverse line drain connection is also provided in forward gear as in neutral position of valve V. A special relief passage lconnects the peripheral brake plate spa to end groove 59 of valve V as indicated in Fig. 2, to facilitate clutch release by relief of trapped `oil, which is quickly spent by the centr'ifugal force of the oil.

which brake 20 takes While it is appreciated that common use of a,

transmission oil body for both servo and lubrica-v tion purposes is generally old, it will be appreciated that the present invention provides special lubrication facilities for the gearing by direct feed from the clutch and brake actuator passages thru pipe 15, outlet 16, passages 13, 14, |01, |00, |09 and the other connections shown.

- This system possesses elements of novelty in combinations not heretofore providedso 'that when the servo system is energised by the barrel valve V, and extra supply of lubrication oil is added to that normally available. The shroud arrangement at 99 with respect to member 22 provides a metered lift of lubricant to the reduction gearing of Figs. 1 to 3, and delivers the excess oil thru passages not shown, to the sump |00d. It was stated preceding that a valve 94' could be used in the feed line to cylinder 59 for the reverse brake zo. This is sho/wn in Fig. sa, the prime numbers corresponding to valve and valve port elements of Figs.' 1 to 3, 6 and 8. Since a full description is given above for valve 94, it is not' deemed necessary to re-describe the operation of valve 94' except to state that since the casing |00 does not revolve, the valve pressure force may be calibrated exactly by spring |02 for its operative responses.

In the foregoing description we have stated in considerable detail the many and various advantages to be derived from the novel features of the construction herein described. It is not deemed necessary to repeat them, except to emphasize the durability and fool-proof character of the invention, and its ability to handle heavy torques in a mechanism occupying a very small space.` The device of the invention has been built and operated satisfactorily under heavy loads continuously applied, and all experimental tests verify the successful nature of the various features as combined in the invention.

It is obvious that one skilled in the art and equipped with the teachings herein may build `a counterpart mechanism in which many small modifications and variations will occur, but it is believed proper to state at this point that the specific disclosure embodied in the present description and drawings is only by way of example, and that the invention herewith is only limited in scope by the appended claims given below.

We claim:

l. In power transmission actuation and control systems the combination of an engine-connected clutch drum, a cylinder formed in said drum, a iluid-pressure-actuated friction clutch having an actuating piston recessed in said cylinder, a fluid pressure producing pump, a conduit supplied by said pump leading to said cylinder, an exhaust conduit leading from said cylinder, a valve responsive to the pressure in said i'irst conduit for admitting said pressure to said cylinder, and a second valve rotating with said drum arranged to permit free flow of duid between said conduits and subject to centrifugal force for blocking the said flow between said conduits to create a building-up of the pressure delivered to said cylinder by said pressure-responsive valve in proportion to the speed of rotation of said drum, and thereby cause said clutch to transmit torque, by force applied to said piston.

2. In the combination set forth in claim 1, the sub-combination of a yielding element effective to provide a predetermined resistance to the pressure actuation motion of said first-named valve and a second yielding element rotating with said second named valve effective to oppose the action of centrifugal force upon said second valve in order to establish a predetermined low speed value at which said second valve will open, and of a manually operable valve in said first named conduit effective to cut of! the feed of said pump to said cylinder and thereby cause said pressure responsive valve to relieve pressure from said cylinder thru the action of said first yielding element.

3. In the combination set forth in claim 1, the sub-combination of a manually controlled pressure directing valve in said first conduit operative to deliver said pump pressure to said cylinder or to cut off said pump pressure therefrom, at will.

4. In marine reverse gearing, an engine shaft, a load shaft, a clutch mechanism adapted to connect said shafts directly, a planetary gear train adapted to connect said shafts indirectly, said train including a sun gear constantly rotating with said engine shaft, an annulus gear, a planet carrier constantly rotating with said load shaft, a pair of meshed planet gears supported on said carrier dimensioned such that one of said meshed pair of meshes with said sun gear and the other with said annulus, a brake mechanism adapted to arrest rotation of said annulus, a drum rotating with said engine shaft enclosing said clutch mechanism and connected to drive said sun gear, a housing supporting said load shaft, power actuator devices for each of said mechanisms consisting of actuator pistons, one located in a cylinder of said drum and the other in a cylinder formed in a web of said housing adjacent said gear train, a fluid pressure supply, a valve located external of said housing adapted to deliver supply pressure selectively to actuate said pistons alternately, and a system of delivery passages connecting said devices to said valve consisting of one path lnsaid housing continuous with a passage in said load shaft leading to a feed passage in said drum for said clutch cylinder, and a second path in said housing leading directly to the cylinder of said second named device.

5. In marine reverse gearing providing direct coupled drive between power and load shafts and reverse reduction drive therebetween, the combination of a power-connected drum and a propeller shaft, of driving means constantly connecting the drive of said load and said propeller drive between said drum and said load shaft. said' train consisting of a sun gear rotating with said drum, a planet carrier rotating with said load shaft, an annulus gear adapted to be braked by said reaction member, and planet gearing supported on said carrier meshing with said sun and said annulus gears, the arrangement of said planet gearing consisting of a pair of meshed planet gears one of which meshes with said annulus and the other of which meshes with said sun gear, and controls for said mechanism and said member operative to cause graduated initial drive and direct connection of said drum and said shaft by said mechanism and operative to cause alternate actuation of said member for establishing reverse drive between said drum and load shaft.

6. In marine gear drives, driving and drivm shafts, a friction clutch adapted to cnect said shafts, an actuating mechanism for said clutch adapted to be actuated by fluid pressure for eatablishing the drive between said shafts, a reverse gear train adapted to transmit reverse torque between said shafts, a torque-establishing member for said train having an actuating mechanism adapted to be actuated by fluid pressure, fluid pressure actuators for each of said actuating mechanisms, pressure feed conduits leading to said actuators, a pressure supply system arranged to provide full actuating pressure for said clutch and for said actuators for causing delivery of predetermined forward or reverse driving torques between said shafts, a pressure directing valve operative for selective connection of said pump supply system with said feed conduits, and pressure responsive valving in said system operative to respond to the existing pressures in said conduits for maintaining the actuating action of said actuators upon said mechanisms at all pressures above given pressures corresponding to the required predetermined drive torques, and Operative to respond to lower pressures within said con-duits for relieving the actuating action of said actuators, the action of the pressure responsive valving resulting in the avoidance of partial loading inadequate to prevent continued slip of the particular mechanism selected for actuating by said directing valve.

7. In a marine reverse gear an engine shaft, a load shaft, a gear train embodied in said gearing consisting of a sun gear rotating with said engine shaft, a gear carrier rotating with said load shaft, a meshing planet gear pair supported for rotation on the carrier, one of said planet gears of said pair meshing with said sun gear, an annulus gear meshing with the other of said planet gear pair said gear train being arranged to provide reverse drive reaction in said train, friction members one of which is operable to establish direct drive between said shafts and another of which is operable to establish reverse drive by stopping said annulus gear, fluid pressure actuated mechanisms each operative to load one of said members for establishing said drives, a fluid pressure supply pump with pressure connections leading to each of said mechanisms, control valving for alternately directing the fluid pressure of said pump selectively to said mechanisms for alternate actuation thereof, a pressure regulating valve responsive to the pressure of one of said connections and thereby operative to release the pressure acting on one of said members at a preassunse determined low pressure of said connection, and a second valve operative in response to a predetennindlow speed of said engine shaft to release the pressure acting on either of said members.

8; a "marine reverse gear unit consisting of xedratiofgearlng providing forward and reverse torque pathsbetween power and load shafts, equipped with forward drive establishing mechanismoperable at one speed ratio and equipped with" reverse drive establishing mechanism operable at another ratio thru said gearing, an engine shaft driving said powershaft, a transmission shaft of said gearing adapted to drive said load shaftga non-rotating gear casing for said gearing, a fluid'pressure servo and lubrication pump driven by said engine shaft, a selector control valve mounted on said casing connected to the output of said pump, forward and reverse gear elements included in said gearing, for providing said torque pathss'upporting bearings for said elements located in said casing, a friction clutch for connecting said engine shaft to said transmission shaft toestablishsaid forward drive torque path, an actuator-for said reverse drive-establishing mechanismfand a' second actuator for said friction clutch,``said actuators including separately operable pistonsfor loading said mechanism and said clutch, cylinders for said pistons, lubrication passages for said gearing elements, conduits in said casing"connecting said control valve with each of said cylinders, and branch feed connections leadingfrom` said conduits to said gearing lubrication passagesand to said fixed ratio gearing operativefto deliver gear lubricant from said pump in accordance` with the presence or absence of actuating pressure in said conduits as selected by said controll valve;`

9; In power transmission control devices, an engine shaft'and a transmission shaft, a change speed transmission having plural input power connectionsmto said engine shaft, one of which drives a constantly meshed gearing train adapted to provide reverse drive of said transmission shaft, theother of said connections constituting a frictionclutch for connecting said shafts, a reverse drive-establishing mechanism for said gear train and1 an 'actuating mechanism for said clutch, said mechanisms each including friction membersto be actuated, a duid pressure supply system for operating said mechanisms consisting of a supply pump, fluid pressure actuators for said mechanisms and conduits adapted to connect the actuators to the pump, devices for controlling the drive ofv said transmission consisting of valving located in saidv conduits which valving includes pressure-regulating valves automatically operative ttrgovernvv the degree of pressure acting in said actuators, and a selector valve connected to saidjpump and said `conduits operativetotselect`v actuation of one or `the other of said actuators, operative' tocontrol the period of action of said pressure-regulating valves, and further operative in one selected position to cause release of drive by both said mechanisms.

10. In the combination set forth in claim 9, the further combination of a valve included in said pressure regulating valves and responsive to the varying degree of actuating fluid pressureV in one of said conduits, said pressure responsive valve being operative to admit pressure to one of said fluid pressure actuators or to relieve the pressure therefrom, said selector valve being rotatable to positions in which it is effective to relieve pressure from or to deliver-pressure to said conduits,

the pressure in said conduits and subject to the speed of said engine shaft, said centrifugal valve being effective to set aside a selected delivery of pressure by said selector valve to one of said conduits leading to one of said actuators and effective thereby to limit the selective drive-controlling action of said selector valve at speeds of saird engine below a predetermined minimum spe 12. In power transmission controls, an engine shaft and a transmission output shaft, a changespeed gearing having plural input power connections to said engine shaft for driving said output shaft, said gearing containing a train of reverse drive gears, said connections including a friction clutch member arranged to establish the drive of said output shaft from said engineshaft, a drive-establishing friction member for said reverse drive train. fluid pressure-operated actuating mechanisms for each of said members, a fluid pressure supply. a fluid pressure delivery system fed by and connected to said supply and including valving adapted to control delivery ofV the fluid pressure of said supply to saidmechanisms for causing operation thereof, pressure feed connections between said valving and said mechanisms, pressure regulating valves in said valving and controlling the pressure in said con-'- nections and made effective lby the pressure of said supply and by rotation of the said engine shaft, a pressure operated piston adapted to apply driving engagement to one of said mechanisms for loading one of said members and responsive to the controlled pressure provided by said regulating valves, a device for providing a predetermined resistance to the rise of duid pressure applied to said piston,. and a driveselecting control valve of said control-system valving connected to deliver actuating pressure to said feed connections and to said shift actuators so that said regulating valves determine the degree of loading actuation of the said mechanism upon the said member by said piston acting against the device, during said driving engagement.

13. A power transmission comprising an engine shaft, a driven shaft, a change-speed transmission adapted to connect said shafts having plural input power connections, two friction members for selectively establishing drive between said shafts. said transmission providing multiple power-delivering paths between said input power connections and said driven shaft; a, iiuid pressure control and actuation system for said transmission including actuators for said friction members, a pressure producing pump. conduits connecting said pump with said actuators. valving in said conduits subject to the speed of said engine shaft for automatically controlling the actuation of said friction members by said actuators. fiuid-pressure-directing valving operative to direct fluid pressure selectively thru said conduits to said actuators, and a pressure-responsive valve effective to control the effect of said valving for providing automatic uncoupling of one of said .i members in accordance with predetermined assises 18 lowering of the delivered pressure of said pump.

14. In the combination set forth in claim 13, the sub-combination of said directing valving being controlled by manually-operable mechanism, and said fluid pressure being further subject to the action of said pressure responsive valve in providing changes in the establishing of the drive from one of said members to another.

15. In the combination set forth in claim 13, the sub-combination of a line pressure regulating valve for said pump, of manually-operable control mechanism for said valving and of a fluid pressure circuit of said system connecting said member-actuators, pump, conduits, valving and said regulating valve, operative so as to provide changes in said actuator pressure other than the pressure initially selected by said control mechanism and provided by said pump.

16. In avariable speed ratio power transmission including gearing adapted to transmit drive in forward and reverse directions between driving and driven shafts, a pair of controllable torque-establishing members for providing drive connections between said shafts at one-to-one forward drive and at reduced reverse speed ratio thru said gearing, a fluid pressure supply system including a pump made operative by rotation of said driving shaft, actuators .connected to said system operable by said fluid pressure for controlling said membersVan automatic centrifugal device for regulating the degree of actuation of said actuators, and automatically operable valving responsive to a given effective pressure of said supply system for directing said fluid pressure to said actuators and operable for relieving same from said actuators when said effective pressure drops below a predetermined value.

1'?. In the combination set forth in claim i6, the sub-combination of said drive connecting members including individually actuable actuating mechanisms for providing said drive connections, and of a manually-operable valve operable to control connection of said pump with said actuators, said centrifugal device and said valvng18. In the combination set forth in claim 16, the sub-combination of actuator conduits of said system, of said centrifugal device being driven by said driving shaft and of pressure connections joining said centrifugal device with said conduits for connecting said supply system with said iluid pressure operated actuators.

19. In the combination set forth in claim 16, the sub-combination of manual control apparatus, and of a selector valve operative to initiate the fluid-pressure-responsive action of said automatic valving and further operative to provide a choice of speed ratio of drive between said shafts as determined by the said members.

20. In the combination set forth in claim 16, the sub-combination of control apparatus for said valving operative to initiate the fluid-pressure response action of said valving and subject to the over-ruling action of said centrifugal device.

2l. In the combination set forth in claim 16, the sub-combination of driving drum fastened to said driving shaft and acting as a housing for one of said drive connections and said members, of reciprocable elements of said actuators effective to cause one of said connectionsto drive while disengaging anotherY of said connections, and of said automatic centrifugal device consisting of a valve mounted in said drum, responding to the speed of said drum and eifective to control the actuation of a member connection made en'ective to drive by one of said actuators.

22. In the combination set forth in claim 16. the sub-combination of said torque-establishing members including friction discs loaded by said actuators actuable for selective coupling of said shafts with drive-connecting elements of said members, and of a pressure directing valve connected between said pump and said actuators operative for determining of shift of said members to forward or reverse position under said fluid pressure actuation, said device and said valving lbeing effective to provide graduated coupling of the torque of said shafts by said members with said discs and said elements.

23. In a forward and reverse gear drive for marine power Plants, the combination of a driving shaft, a driven shaft, a change-speed transmission adapted to provide plural drive connections between said shafts, gearing included in said transmission for driving said driven shaft reversely from said driving shaft, thru one of said connections, torque-establishing members of said connections alternately operable for selectively connecting the said shafts for forward or reverse drive, loading mechanisms for each of 'said members, a fluid pressure supply system y having fluid pressure actuators for each of said mechanisms, a pressure producing pump driven by one of said shafts and conduits adapted to connect said pump with said iluid pressure actuators, automatic valves in said conduits effective to regulate the operation of said mechanlsms by said fluid pressure actuators, one of said valves responding to the speed of said driving shaft, valving controlling the pressures delivered by said conduits and directing same to said actuators, and a fiuid-pressure-operable valve included in said automatic valves and responding to the effective pressure delivered by said pump to said conduits for establishing at least one of said driving member connections between said shafts, or for disconnecting the drive of said member in response to a predetermined lower pressure acting upon said valve.

2i. A power transmission device for providing selective automatically-connected drive between driving and driven shafts, said device including plural friction members adapted when actuated to establish drive between a driving shaft and a driven shaft at two different drive ratios, a fiuid pressure supply system for said device duid pressure actuators for said friction members fed by passages of said supply system and controlled by a speed-responsive valve connected to said system, said valve being effective to control the period of actuation of said members by said actuators, selector valving connected to said passages and movable for initiating the actuation of or releasing of said members, and a valve controlled in accordance with the effective pressure of saidl supply system for determining the actuation period of at least one of said members.

25. In the combination set forth in claim 24. the arrangement and operation of said supply system, said speed and pressure responsive valves, said selector valving and said supply and actuators in the fluid connecting circuit being such that for given low speeds of said speedresponsive valve, the said fluid pressure actuators are rendered ineffective to establish drive by said members.

26. In the combination set forth in claim 24, said power transmission device including gear- Y from said supply system conduits during the interval when said selector valving is positioned to select drive thru said gearing,

27. In the combination set f ortb in claim 24, a driving drum fixed to said-driving shaft. fluid pressure passages in said drum leading to a cylinder enclosing a piston of said actuators, and

bores in said drum connected to said passages,v

said bores accommodating said speed, responsive valve and accommodating said fluid pressure-operable valve.

28. In the combination set forth in claim 24,

a transmission driving drum ilxed to said driving shaft, a cylinder and piston for said actuators located in said drum, said speed responsive valve being located in a bore of said drum operatively connected with said cylinder and said pressure-responsive valve being located in a second bore of said drum likewise operatively connected with said cylinder and said lastnamed valve being counter-balanced against respouse to Vcentrifugal force created by rotation of said drum. y

29. A power transmission device comprising a power input shaft, a power output shaft, a change-speed mechanism adapted to provide selective forward or reverse speed ratio drive between said shafts thru plural drive trains therebetween, a plurality of selectively actuable friction members for establishing connecting of said shafts thru saidr trains, fluid pressure actuators for eifecting the loading of said members including an actuating piston and cylinder for one of the members, a iiuid pressure supply pump adapted to provide pressure for said actuators, a speed responsive valve for controlling the pressure delivered by said pump to said actuators, a manual control, a second valve for modifying the delivering action of said iirstnamed-valve in accordance with movement of said manual control, and valving for varying the loading effect of said iluid pressure actuators upon said one of said friction members, said valvlng including a valve responding to predetermined changes in the pressure supplied to said actuators, said latter valve being operative to increase the said loading effect above a given pressure acting upon it and to diminish said loading effect at a pressure less than said given pressure. Y g

30. A forward-and-reverse marine gear unit of the epicyclic type having a power-input sun gear, a carrier, a set of meshing double planet gears supported on the carrier, one of which is meshed internally with said sun gear, a load-shaft connected to said carrier, an annulus gear meshing internally with the other of said double planet gears and effective when braked to cause said carrier and said shaft to revolve in reverse, supports for said sun and annulus gears operative to permit -equalizing load adjustment of said sun and annulus gears with respect to said planet gears, braking mechanism effective to brake the rotation of said annulus gear, during which interval said equalized load adjustment occurs, said supports consisting of spline drive connections for said sun gear and of a brake plate attached to said annulus gear and arranged for limited axial motion between axially fixed stop elements.

31. In power gear units, a power shaft and a load shaft, a gear train arranged to transmit torque between said shafts including an annulus 18 gear and disc braking mechanism means'therefor, a driving drum connected to said power shaft and constantly driving a sun gear of said train, a clutch plate and hub mounted to rotate with said driven shaft and arranged so as to be housed within said drum,` a disc actuator mechanism for said clutch plate iorgripping same to said'drum. a planet gear carrier of said train xed to said driven shaft, meshing sets of planets) of said train spindled separately in said cari/'ier having an inner set meshing with said sun gear and an outer set meshing with'said annulus, and supporting structures for said sun gear and said annulus gear operative to permit equalization of tooth load on either gear during an interval when said clutch actuator mechanism releases said plate and said braking mechanism stops rotation of said' annulus gear, said means consisting of spline drive connections for said sun gear and of axially loaded stop elements for said disc means.

32. In the combination set forth in claim 3l, the sub-combination of fluid pressure operated actuators for said mechanisms consisting of axially movable pistons and of an arrangement of said supporting structures permitting axial motion of said clutch plate and said braking disc means when the fluid pressure operated actuators are energised for loading either of said disc mechanisms.

33. In a reverse gear drive of the planetary type for marine use, the combination of an engine shaft, a load shaft, a clutch consisting of a friction member adapted to be gripped by a loading mechanism actuable to cause said clutch to connect said shafts directly, a planetary gear of which is dimensioned to mesh internally with said sun gear and the other of which is dimensioned to mesh externally with said annulus gear, of a carrier for said planet gears fixed for rotation with said load shaft, a brake mechanism for said annulus gear, power actuators for loading said mechanisms, selectively operable controls effective to alternate the loading action of said actuators upon said mechanisms, and of a regulating device for said actuators effective to establish variable loading actuation of 'said clutch mechanism when said controls select said power actuation for said clutch mechanism.

34. In the combination set forth in claim 3l, the sub-combination of bearings for the support of said load shaft in said housing, and of lubrication passages leading to said bearings, said passages being fed by the pressure delivered by the said valve to said first-named pressure delivery path.

35. In a marine gear control for a power transmission having a direct drive clutch between input and outputshalfts, a clutch loading mech= anism for same, and having a reduction gear drive train adapted to connect the said shafts with an energisable friction member for establishing the'drive of the said train, the combination of a duid pressure actuation and control system for the said clutch mechanism and said friction member consisting of a fluid pressure actuating supply pump, of iiuid pressure operated actuators for each clutch mechanism and said member, feed conduits leading to said actuators, of a iiuid pressure directing valve movable to deliver the pressure of said pump alternately to said actua- 19 tors thru said conduits, and of a valve adapted to respond to the presence orv absence of pressure in either of said conduits and in the absence of said pressure to connect the said conduits to exhaust.

CHARLES J. McDOWALL. JOHN E. STORER. Jn. IIEILMIIIIR A. RICHARDS.

REFERENCES CITED The following references are of record in 111e of this patent:

Number l Number 

